Sewing machines capable of embroidery sewing have been conventionally provided in the field of household sewing machine also. Such sewing machine capable of embroidery sewing generally includes, in its sewing machine body, a frame moving unit for moving an embroidery frame holding a workpiece cloth. The embroidery frame is provided with an inner frame and an outer frame and a workpiece cloth is clamped therebetween. The embroidery frame is detachably attached to the carriage of the frame moving mechanism by horizontally sliding the same in the longitudinal direction (from the front side to the rear side).
The sewing machine sews embroidery patterns on the workpiece cloth by moving the carriage having the embroidery frame attached thereto freely in the horizontal direction (X- and Y-directions) by the frame moving unit. The embroidery frames are interchangeable with frames of a plurality of types in various shapes and sizes such as round or rectangular shapes depending upon the size (shape) of the embroidery or the workpiece cloth.
Nowadays, a clamp-type embroidery frame provided with a lower frame and an upper frame for clamping the workpiece cloth therebetween and a clamp mechanism for retaining the workpiece cloth by pressing the upper frame against the lower frame have been suggested and reduced to practice to replace the conventional embroidery frame provided with the inner and outer frames which were of general use. For instance, Japanese Patent Application H08-252387 A (page 4, FIG. 3) discloses a clamp type embroidery frame provided with a base frame (lower frame) in frame-form; a presser frame (upper frame) clamping a workpiece cloth between the base frame; and a connecting member connecting the presser frame vertically swingably to the base frame; and a pair of left and right clamp mechanism unlockably pressure-locking the presser frame to the base frame.
Embroidery frames of general use provided with conventional inner and outer frames have been designed in relatively low vertical height (being generally thin). Thus, regardless of the position in which the embroidery frame (carriage) is stopped, the embroidery frame is allowed to pass through between the embroidery presser foot and the needle plate upper surface without interference, thereby allowing smooth attachment/detachment of the embroidery frame by being slid in the longitudinal direction. However, the above mentioned clamp-type embroidery frame, as compared with the aforementioned general embroidery frame, has greater vertical dimension at its clamp mechanism portion. Thus, as for the clamp-type embroidery frame, the attempt to attach/detach the embroidery frame at a given stopped position may cause the clamp mechanism portion to fail in passing through the space between the embroidery presser foot and the needle plate upper surface and consequently be damaged by colliding with the embroidery presser foot.
In this context, Japanese Patent Application 2002-18166 A (page 4, FIG. 2) discloses a compact sewing unit creating patches by mounting a cloth to a compact embroidery frame. The sewing unit is provided with a sewing unit body for sewing embroidery on a cloth; a safety cover for covering a sewing unit body; and an embroidery frame detachably attached to the sewing unit and a sewing cartridge equipped with a hollow sewing needle. Since the sewing unit is structured such that the sewing unit body is covered by the safety cover, the embroidery frame is arranged to be moved to a predetermined removing position (position situated outside the opening of the safety cover) for removing the embroidery frame after completion of embroidery sewing.
In the light of the above, a sewing machine provided with a clamp-type embroidery frame may also employ a configuration of moving the embroidery frame to a predetermined removing position (position in which the clamp mechanism does not interfere with the embroidery presser foot upon attachment and detachment of the embroidery frame). However, when the configuration of moving the embroidery frame to a predetermined removing position on a consistent basis after every completion of embroidery sewing is employed to a sewing machine capable of using both the embroidery frame of general use provided with inner and outer frames and the clamp-type embroidery frame, the following problem is encountered. That is, the generally used embroidery frame being detachable at any given position makes an unfruitful movement to the predetermined removing position, consequently reducing work efficiency.